Direct current remote indicating system



Feb. 17, 1942. e. v. RYLSKY DIRECT CURRENT REMOTE INDICATING SYSTEM 2Sheets-Sheet 1 Filed Oct. 28, 1940 INVENTOR 9 :9

ATT0RNEY$ Gre BY Feb. 17, 1942. G. v. RYLSKY 2,273,596

DIRECT CURRENT REMOTE INDICATING SYSTEM Filed Oct. 28, 1940 2Sheets-Sheet 2 l I k I01 s 117 a 113 I80 I51 12 P INYENTOR (176 0119llll lslfy. M 'f (m ATTORN EY$ Patented Feb. 17, 1942 DHEECT CURRENTREMOTE INDICATING SYSTEM Gregory V. Rylsky, New York, N. 32., assignorto Bendix Aviation Corporation, Bendix, N. J., a

corporation oi Delaware Applicationoctober 2a, 1940, Serial No. 363,231

(or. iii- 351) .12 Claims.

This invention relates to remote indicating systems of the type whereina local minute movement of a sensitive instrument may be accurately andrapidly reproduced at a remote or distant point.

it has been the general practice in the past to provide Autosyn orSelsyn systems for reproducing indications at a remote point. In the useof these systems the initial movement has to be of a substantial valueso as to move the transmitter rotor of the system and at the same timeovercome the reactive forces set up by the moving transmitter rotor.Obviously, such systems are impractical and undependable when it isdesired to transmit the small movements of sensitive instruments such asmagnetic or gyroscopic compasses generally provided upon aeroplanes orseagoing vessels.

The reason for the inadaptability of the present systems known in thetelemetric art lies in that any attempt to connect a transmitter rotorto a movableelement of a sensitive instrument providing a small torquewould result in relative movement between the rotor and the element or,

it may even beithat the reactive force upon the rotor would be greatenough to prevent movement of the element.

One of the objects of the present invention is to provide a novel remoteindicating system for overcoming the above-mentioned difficulties and,further, one adapted to accurately and rapidly reproduce at a remotepoint minute movements of sensitive instruments such as compasses, forexample, which generate a very small torque during their movement. It isspecifically to be understood, however, that the invention is notlimited to use with compasses only, but may be used as. well toreproduce movements of gyroscopic and other sensitive instruments.

Another object is to provide a novel remote indicating system of thedirect current type for cutting down considerably the weight of themechanism.

A further object of the invention is to provide a novel remoteindicating system having a transmitter provided with temperatureresponsive resistors, whereby currents in the transmitter are varied asa function of the movement of a sensitive instrument, and the varyingcurrents are communicated to the stator of a repeater setting up aresultant magnetic field in the stator thereby'moving a pointer attachedto an element movable with the resultant magnetic field. The fol- Theabove and further objects and novel ieatures will more fully appear fromthe following detailed description when the same is read in connectionwith the accompanying drawings. It is to be expressly understood,however, that the drawings are for purposes of illustration only and arenot intended as a definition of the limits of the invention, referencefor this latter purpose being had primarily to the appended claims.

In the drawings, wherein like reference characters refer to like partsthroughout the several views:

v Figure l is a front view in sectlon, partially diagrammatic, of oneembodiment of the invention; Figure 2 is a top elevation, with the topremoved, of the noveltransmitter disclosed in I Figure 1;

will be accurately reproducedat a remote point without disturbing theindications of the sending mote indicating mechanism of the characterFigure 3 is a developed view of the movable member of the transmitter ofFigure 1, in relation to the transmitter and repeater circuits;

Figure 4 is a front view in section, partially diagrammatic, of anotherembodiment of the invention; Figure 5 is a developed view of anotherform of the movable transmitter member of Figure 1,

, in relation to a second arrangement of the cirabove described adaptedto be energized by direct current, thereby eliminating the necessity ofa special source of alternating currentand thus cuit embodying thetemperature responsive elements: and r Figure 6 is a wiring diagram oi afurther embodiment of the novel transmitter circuit arrangement of theinvention.

In the embodiment illustrated in Figure 1, the remote indicating systemis shown as comprising a transmitter device and a receiver device,generally designated at I and II, respectively. The novel transmitterdevice I3 includes a cylindrical housing I2 provided with longitudinalslots I3, I4 and I in the cylindrical surface thereof and spaced 120apart from each other. Surrounding: the housing I2 is a secondcylindrical housing, I3 adapted to rigidly support three temperatureresponsive elements or resistors I1, I3 and I3 likewise spaced 120 apartoutside the outer periphery of housing I2 and substantially adjacent theslots I3, I4 and I5 thereof for a purpose to be more fully describedhereinafter.

The remote receiver device includes a stator comprising coils 23, 2| and22 joined at a common point 23. .Suitably mounted with the receiverstator for rotation thereby is a magnetic rotor element 24 havingattached thereto a pointer 25 superimposed for movement over a suitablescale 23.

The temperature responsive resistors I1, I3 and I3 are arranged inparallel in the circuit, as better shown in Figure 3, and one end ofeach of the resistors I1, I3 and I3 is connected to coils 23, 2| and 22by means of conductors 21, 23 and 23, respectively. The opposite ends ofthe resistors are connected by way of a common lead 33 to one side of asuitable direct current supply source, such as a battery 3|, while thecommon point 23 of the receiver coils is connected with the. other sideof the supply source by way of a conductor 32, thereby completing thecircuit.

A sensitive instrument of any well known type, such as a magneticcompass 33 having magnets 34 and II, for example, may be rigidly securedin any suitable manner by way of a rotatable support 33 to a craft at apoint of minimum magnetic disturbance. As the craft utilizing the abovedescribed remote indicating system deviates from a predetermined course,the magnets 34 and 35 of compass 33 move angularly relatively to thecraft so as to indicate at all times the direction of the magneticnorth.

It is the relative angular movement of the compass magnets that it isdesired to reproduce at a remote point, and this is accomplished byproviding a magnetic coupling between the compass magnets and thetransmitter rotor to be more fully described hereinbelow.

The transmitter rotor comprises a rotatably mounted vane 31 constitutinga truncated hollow cylinder as shown in Figure 1. The rotor vane 31 ismounted within the housing I2 havingits outer surface closely adjacentthe inner periphery of the housing I2 and variably covering the slotsI3, I4 and I5 as better shown in Figure 2. A shaft 33 suitably mountedfor rotation in housing's I2. and I6 is secured to the base of the rotorvane 31 for angularly moving the latter in response to compass movementby way of a follower I magnet 33 suitably secured to the free end ofshaft 33. The rotation of shaft 33 and vane 31 is effected by way of thefollower magnet 33 which tends at all times to maintain a predeterminedangular position with respect to the compass magnets 34 and 35.

A stream of air, which may be cooled, is led into the interior of thehousing I2 from any suitable supply source (not shown) by way of inlet43 formed integrally with or secured to the top of housing I2. The rotorvane 31 acts as a valve for directing the air into the unobstructed slotthereby cooling the related resistor adjacent the slot and at the sametime preventing air flow to the slots covered by the vane. The airpasses over the resistor to the interior of housing I3 and is ledtherefrom by means of a suitable outlet 4|. It is to be understood,however, that instead of a stream of cool air, the system will operateequally as well where a negative pressure or vacuum is used.

In operation, as the craft departs from a predetermined course, thecompass magnets 34 and 35 move relatively with respect to the craft andsince the transmitter device III is fixedly secured with the craft, therotor vane 31 thereof is moved angularly an amount proportional to thecompass movement due to the movement of the follower magnet 33 inkeeping its predetermined angular relation with respect to. the compassmagnets.

Upon movement of the transmitter rotor vane 31, to the position shown inFigure 1, for example, the stream of cool air will be prevented frompassing to slots I4 and I5 but is directed to pass through slot I3 andover resistor I1, cooling the latter, thereby increasing the currentflow therein and in related coil 20. Since the resistance of resistorsI3 and I3 remains constant and in this case greater than that ofresistor I 1, smaller 'currents flow therethrough and, therefore, in

coils 2| and 22.

As is well known, magnetic fields are set up about a conductor carryinga current and, therefore, the magnetic fields surrounding coils 2| and22 will be substantially equal and of smaller'intensity than themagnetic fieldsurrounding coil 23 having the greater current flow. Theresultant magnetic fleld, therefore, will be greater about coil 20 andthe magnetic pull exerted thereby upon magnet 24 will, cause movementthereof and of pointer '25 over scale 23. The pointer 25, therefore, ismoved angularly into positional agreement with the direction of thecompass magnets 34 and'35.

Upon further rotation of vane 31 due to additional craft deviationanother resistor is uncovered while the remaining two are covered andthe cool air impinges upon the uncovered resistor thereby decreasing thevalue of its resistance and increasing current flow therethrough. Thiscurrent change is communicated in the same manner to the related coiland the direction of the resultant magnetic field changes therebyangularly moving the receiver rotor 24 and pointer 23 to a newpositional agreement.

The action of the vane 31 upon the resistors I1, I8 and I3 may be betterunderstood upon reference to Figure 3, wherein 42 represents adevelopment of the vane 31 with the relation of its effective edge 42ato the resistors I1, I3 and I3.

From the above, it will now be apparent to those skilled in the art thata novel remote indicating system has been provided for remotely,indicating small movements of a sensitive instrument without thenecessity of any mechanical connection between the movable sensitiveelement and the transmitter rotor.

Similar to the arrangement shown in Figure 1, but differing chieflytherefrom in the transmitter rotor vane, a second embodiment of theinvention is shown in Figure 4. Like parts in this view similar to partsin Figure l are designated with the same reference numeral plus 100.

The arrangement of Figure 4 consists chiefly of a transmitter device H0and a receiver device Ill. The transmitter H is provided with acylindrical housing I0l having an outlet I02 secured thereto or formedintegrally therewith while the base of the cylinder is provided withslots H3, H4 and H5. Rigidly mounted within the housing l0l uponsuitable supports closely adjacent the slots H3, H4 and H5 are thetemperature responsive resistors H1, H8 and H3.

The receiver device III comprises stator coils I20, I2I and I22 whichare connected at one vend to a common lead I32 and have their free endsconnected to one of each of the temperature responsive resistors H1, H8and H9, respectively, by means of leads I21, I28 and I20. Thetemperature responsive resistors are arranged in parallel and have theirfree ends connected by means of lead I30 with one end of a suitabledirect current supply source I3I while the other end of the source isconnected with the common lead I32 to the coils. The stator coils I20,I2I and I22 are provided with a magnetic rotor member I24 carrying apointer I25 movable over a scale I25.

A compass I33 suitably mounted upon the craft is provided with magnetsI34, and I35 adapted for relative movement with respect to the craftduring deviation of the latter from a predetermined course. Followingthe relative movements of the compass magnets I34 and I35, is a followermagnet I39 secured to one end of a shaft I38 carrying at the other endthereof an eccentrically mounted disc I31 which is adapted to pass overthe slots H3, H4 and H5 as better shown in Figure 4. Since thetransmitter device H0 is fixedly secured with the craft during coursedeviation of the craft, the follower magnet I33 will follow the relativemovements of the compass magnets I34 and I35 and thereby rotate the vaneI31 to a position such, for example, as shown in dotted lines in Figure4.. Assuming the outlet I02 to be secured with a source of vacuum, theslot H3 being unobstructed, the resistor H1 will be cooled and thecurrent flow therein increased, increasing current flow in coil I20whereby the resultant magnetic field formed about the coils will carryrotor member I24 and pointer I25 to positional agreement with thecompass magnets I34 and I35. The action here is substantially identicalto that described in connection with the arrangement of Figure 1 andwill now be apparent to those skilled in the art.

It is to be noted that in the arrangement of Figures 1 to 4, inclusive,only the resultant magnetic field surrounding the coils has been reliedupon, and this for the reason that current flows in the same directionat all times within the coils. A second arrangement can be utilizedwherein the direction of flow of current is varied, thereby varying thedirection of the magnetic field surrounding the coils. For thisarrangement, reference is made to Figure 5 of the drawings, wherein,parts similar to like parts in Figure l have been designated with thesame reference numeral plus 200. v

The transmitter arrangement provided with the resistor circuit of Figure5 is substantially the same as the transmitter arrangement of Figure 1with the exception that the temperature responsive resistors 2I1, 2l8and 2I9 are tapped at their midpoints,: a, b and 0, respec-' tively, andjoined at such points with coils 220,

229. arranged in parallel in the circuit and have their free endsconnected with a suitable supply source and with an additional resistor206 by point of resistor 206.

means of common leads 250 and25I. The free ends of the coils, in thiscase, are joined to the midpoint of resistor 205 by way of lead 205.

The temperature responsive resistors 2H, 2H! and Us are spaced 120 apartabout the inner housing I2 of Figure 1, containing slots I3, I4 and I5and the rotorvane 31 isreplaced with a rotor vane 231 having thedevelopment better shown in Figure 5', whose base contour is similar toand parallel with the contour of its top portion defining the edge 42aof Figure 3.

The operation o'f,this arrangement is the same as that of Figure 1 withthe exception that in the arrangement of Figure 5, current flow in thecoils is reversed thereby reversing the polarity of the magnetic fieldsurrounding the coils. This current reversalis accomplished by movementof the rotor vane 231 which cools one of the resistors at one side ofthe midpoint and at the next interval covers the former portion of theresistor and uncovers the opposite side of the resistor. Assuming thateach of the resistors 2" and 2I9 are equally cooled at both sides of themidpoint while the value of resistor 2! is substantially decreased-atone side of its midpoint due to greater cooling thereof as shown inFigure 5, and further, assuming a 100 volt supply source, the voltage atthe midpoint of resistor 206 would be volts; Since the value of resistor2I8 has been decreased the voltage drop would be smaller and the voltageat the midpoint of resistor 2I8 would be substantially 65 volts. Currentfiow from the source would, therefore. be in the direction of the coil22! and to the mid- The magnetic field generated about coil 22I wouldhave one direction.

Consider now, the reverse of the above, namely,

that the upper portion A of resistor 2I8 were covered and the lowerportion B uncovered and, therefore, cooled. Theoretically, if theresistor portion B were cooled to the point'where the amount ofresistance were negligible, the voltage at the midpoint would be zeroand since the voltage at the midpoint of resistor 206 remains 50 volts,the current flow would be in the direc-- tion opposite from thatdiscussed above, and the magnetic field surrounding coil 22I would bereversed. The field reversal is eifective to pull the magnet rotor 224to a position in agreement Wheatstone bridge arrangements 3I1, 3I8 and3l3 likewise subjected to varying temperature control. One diagonal ofeach of the bridges is connected at one end to each of the coils 320,32I and 322 and at the other end to the free ends of the coils by meansof leads 321, 328 and 3291 respectively, and lead 332, while the cpposite diagonal of each of the bridges is secured with two sides of 'a D.C. supply scurce by way of conductors 352 and 353. .Oppcsite arms of thebridges 3I1, 3l-8 and 3I9 are subjected to the movement of vane 231 ofFigure 5 and the operation is similar to that described in connect-ionwith Figure 5 and the magnetic rotor element 324 is positioned intoagreement with the sensitive element.

Although several embodiments of the present invention have beenillustrated and described in detail, it is to be expressly understoodthat the invention is not limited thereto. Various changes may be madein the design and arrangement of the parts without departing from thespirit and scope of the invention as the same will be understood bythose skilled in the art. For a definition of the limits of theinvention, reference is therefore to be had to the appended claims.

What is claimed is:

1. In a system for indicating angular motion of a movable element of asensitive instrument at a remote repeater, a transmitter deviceelectrically connected with said repeater comprising a circuit having aplurality of temperature responsive resistors arranged in parallel inthe circuit, a source of current for heating said resistors, meansdirecting a flow of air to said resistors, air flow control meansrotatably mounted adjacent said resistors, and magnetic meansoperatively connecting said control means for angular movement with saidelement whereby said control means are actuated for controlling the flowof air to said resistors to vary the temperature of said resistors inaccordance with the angular movement of said element.

2. In a system for indicating angular motion of a movable element of asensitive instrument at a remote repeater, a transmitter deviceelectrically connected with said repeater comprising a circuit having aplurality of temperature responsive resistors arranged in parallel inthe circuit, and a source of current for energizing said resistors toheat them, means for supplying air to vary the temperature of saidresistors, a rotatably mounted valve adjacent said resistors forcontrolling said air, supply, and magnetic means secured with said valveadapted for angular movement with said element whereby said valve isactuated to vary the temperature of said resistors and current flowtherein in accordance with the angular movement of said element.

3- In a system for indicating angular motion of a movable element of asensitive instrument at a remote repeater, a transmitter deviceelectrically connected with said repeater comprising a circuit having aplurality of temperature responsive resistors arranged in parallel inthe circuit and a source of current for energizing said resistors toheat them, means for supplying air to vary the temperature or saidresistors, a truncated cylindrical member rotatably mounted adjacentsaid resistors for controlling said air supply; and magnetic meansconnected to said member whereby said member is actuated to vary thetemperature of said resistors and current flow therein in accordancewith the angular movement of said element.

4. A transmitter device for a remote indicating of fluid pressure whosetemperature differs from fers from that of the temperature responsiveresistors directed toward said slotted portions, and rotatably mountedmeans intercepting the fluid flow from passing through some of saidslotted portions and directing said flow to pass through the remainderof said slotted portions to impinge upon the related resistors adjacentthereto thereby varying the temperature of said last-named resistors andthe current flow therein.

that of the temperature responsive resistors di rected toward saidslotted portions, and a rotatably mounted truncated cylindrical memberfor intercepting the fluid flow from passing through some of saidslotted portions and directing said fluid flow to pass through theremainder of said slotted portions to impinge upon the related resistorsadjacent thereto thereby varying the temperature of said last-namedresistors and the current flow therein.

6. In a system for indicating angular motion of a movable element of asensitive instrument at a remote repeater, a transmitter devicecomprising a plurality of temperature responsive resistors arranged inparallel and electrically connected at their midpoints with the repeaterand having current flowtherein, a rotatably mounted member adjacent saidresistors for covering a portion of some of said resistors during oneposition of said movable element and for covering another portion ofsaid last-named resistors during another position of said movableelement whereby current flow communicated to portions of said repeateris reversed, and magnetic means secured with said rotatably mountedmember adapted for angular movement with said sensitive element wherebysaid member is actuated for varying thetemperature of said resistors andcurrent flow therein in accordance with the angular movepressure whosetemperature differs from that of the normal temperature er saidtemperature responsive resistors, a rotatably mounted member adjacentsaid resistors for directing said fluid against a portion of some 01'said resistors during one position of said movable element and fordirecting said fluid against another portion of said lastnamed resistorsduring another position of said movable element whereby current flowcommunicated to portions of said repeater is reversed, and magneticmeans secured with said rotatably mounted member adaptedfor angularmovement with said sensitive element whereby said member is actuated forvarying the temperature of said resistors and current flow therein inaccordance with the angular movement of said sensitive element.

8. In a system for indicating angular motion of a movable element 01' asensitive instrument at a remote repeater, a transmitter devicecomprising a plurality of temperature responsive Wheatstone bridgecircuits arranged in parallel and electrically connected with therepeater and having current flow therein, a source of fluid pressurewhosetemperature difl'ers' from that of the normal temperature of saidbridge circuits, a rotatably mounted member adjacent said bridgecircuits for directing said fluid against opposite arms of some of saidbridge circuits during one position of said movable element and fordirecting said fluid against the remaining arms of said last-namedbridge circuits during another posi= tion of said movable elementwhereby current flow communicated to portions of said repeater isreversed, and magnetic means secured with said rotatably mounted memberurged for angular movement by said sensitive element whereby said memberis actuated for varying the temperature of said bridge circuits andcurrent flow therein in accordance with the angular movement of saidsensitive element. I

9., In a system for indicating angular motion oi a movable element of asensitive instrument at a remote repeater, a transmitter devicecomprising a plurality of temperature responsive resistors arranged inparallel and electrically connected with the repeater and having currentflow therein, a source of fluid pressure whose temperature difiers fromthe normal temperature of said temperature responsive resistors, arotatably mounted member adjacent said resistors for directing saidfluid against some or said resistors during one position of said movableelement and against another or said resistors during another position ofsaid movable element whereby current flow in the effected resistors isvaried, and magnetic means secured with said rotatably mounted memberadapted for angular movement with said sensitive element whereby saidmember is actuand current source whereby a resultant magnetic field isproduced by said coils, said field moving ated for varying thetemperature of said resistors and current flow thereinin accordance withthe angular movement of said sensitive element.

10. A telemetric system for indicating the angular motion of arotatable'element at a remote I point, comprising a transmitterincluding a pinrality or temperature responsive resistors angularlyspaced about the axis of rotation of said element, a source of currentfor energizing said resistors to heat them, means for supplying a flowor air toward said resistors to vary their temperatures to thereby varythe current flow therein, means actuated by said rotatable element forcontrolling the air flow to said resistors to vary the temperaturethereof and the current flow therein in accordance with the angularmovement or said element, a remote receiver comprising a plurality ofcoils connected to said resistors angularly in accordance withtheangular movement of the rotatable element at the transmitter,rotatable magnet means providing a field which reacts with saidresultant field to rotate said magnet means, and indicating meansactuated by said magnet means.

11. In a system for indicating angular motion of a rotatable element ora sensitive instrument at a remote repeater, a transmitter deviceelectrically connected with said repeater comprising a circuit having aplurality of temperature responsive resistors therein, a source ofelectrical current .for heating said resistors, means directing a flowof air to vary the temperature of said resistors, air flow control meansrotatably mounted adjacent said resistors, and magnetic meansoperatively connecting said control means for angular movement with saidelement whereby said control means are actuated for controlling the flowof air to said resistors to vary the temperature 01' said resistors inaccordance with the angular movement of said element.

12. In a system for indicating angular motion of a rotatable element ora sensitive instrument at a remote repeater which comprises a stator anda magnetic rotor associated with the stator, a transmitter deviceelectrically connected with the stator comprising a circuit having aplurality of temperature responsive resistors angularly GREGORY VRYLSKY.

